File:Operation of trains and station work and telegraphy (1916) (14758855895).jpg

Identifier: operationoftrain02prio (find matches)
Title: Operation of trains and station work and telegraphy
Year: 1916 (1910s)
Authors: Prior, Frederick John, 1858- (from old catalog) comp
Subjects: Railroad trains Railroads
Publisher: Chicago, F. J. Drake & co
Contributing Library: The Library of Congress
Digitizing Sponsor: The Library of Congress

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his in-strument, having first turned the outer guard (Figure122-N) to place, moves the staff into engagement withand revolves drum (Figure 123-D) through one halfturn, using the staff as a handle (see Figure 127) andallows it to roll down the spiral. He then presses hisbell key the prescribed number of times, thus notifyingX that the train is out of the section, which operationalso moves the staff indicating needle at X fromStaff Out to Staff In. The operator at X presseshis bell key in acknowledgment and by doing so movesstaff indicating needle at Y from Staff Out toStaff In (see Figure 127). The machines are nowsynchronized and another staff can be obtained fromeither in the manner above described. The staff being put in the instrument at Y, the cir-cuits for releasing a staff at X or Y would be asshown on Plates 11 and 12 respectively. While it takes some little time to describe the methodof operating the staff instruments, yet, as a matter of fact, 406 RULES FOR MOVEMENT OF TRAINS
Text Appearing After Image:
FIG. 127. ABSOLUTE STAFF INSTRUMENT.Front View of Instrument when a Staff has been Replaced. STATION AND TRAIN WORK 407 the removal of a staff actually takes less than five seconds,and the operation of putting one in an instrument lessthan two seconds, under ordinary conditions. The same methods are followed at each succeedingstaff station, but no two adjacent sections use the samedesign of staff; that is to say, the staff used between Xand Y will not fit the instruments which control thesection between Y and Z. Usually four different designs of staffs are employed inactual practice, to avoid any possibility of their being im-properly used. The Permissive Feature.—While the absolute trainstaff system, where but one train is allowed in any sec-tion, is the ideal arrangement, yet cases occur where itis desirable to allow several trains to follow each othera block at short intervals. This may be done by the useof the permissive system/ which consists of an attach-ment to the absolute m

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